1. Field of the Invention
The present invention relates to a relay communication system including a plurality of relay servers capable of communicating with one another, a plurality of client terminals, and LANs to connect the client terminals to the relay servers, and further, relates to the relay servers for use in the relay communication system.
2. Description of the Related Art
In some cases, client terminals connected to remote LANs communicate with one another beyond a WAN. A virtual private network (VPN) can construct a network looking as if the remote LANs were directly connected to one another. However, it is difficult for the VPN to construct a network having expandability and flexibility.
A relay communication system disclosed in Japanese Patent Laid-Open Publication No. 2008-129991, like the VPN, can construct a network looking as if remote LANs were directly connected to one another. In addition, unlike the VPN, it is easy for the relay communication system to construct a network having expandability and flexibility.
In the relay communication system disclosed in Japanese Patent Laid-Open Publication No. 2008-129991, identification information of the client terminals connected to the respective LANs is shared, whereby the communication among the client terminals is enabled. Specifically, association information between identification information of the relay servers and the identification information of the client terminals is shared in the entire network, thereby enabling the relay servers to relay communication packets among the client terminals.